diff --git a/test/-ext-/bug_reporter/test_bug_reporter.rb b/test/-ext-/bug_reporter/test_bug_reporter.rb
index 6ac5b8f995..e68adeef06 100644
--- a/test/-ext-/bug_reporter/test_bug_reporter.rb
+++ b/test/-ext-/bug_reporter/test_bug_reporter.rb
@@ -16,9 +16,7 @@ class TestBugReporter < Test::Unit::TestCase
     args = ["--disable-gems", "-r-test-/bug_reporter/bug_reporter",
             "-C", tmpdir]
     stdin = "register_sample_bug_reporter(12345); Process.kill :SEGV, $$"
-    _, stderr, status = EnvUtil.invoke_ruby(args, stdin, false, true)
-    stderr.force_encoding("ASCII-8BIT")
-    assert_pattern_list(expected_stderr, stderr)
+    assert_in_out_err(args, stdin, [], expected_stderr, encoding: "ASCII-8BIT")
   ensure
     FileUtils.rm_rf(tmpdir) if tmpdir
   end
diff --git a/test/ruby/test_rubyoptions.rb b/test/ruby/test_rubyoptions.rb
index b1ecef402a..ab0901d1db 100644
--- a/test/ruby/test_rubyoptions.rb
+++ b/test/ruby/test_rubyoptions.rb
@@ -552,18 +552,9 @@ class TestRubyOptions < Test::Unit::TestCase
   def assert_segv(args, message=nil)
     test_stdin = ""
     opt = SEGVTest::ExecOptions.dup
+    list = SEGVTest::ExpectedStderrList
 
-    _, stderr, status = EnvUtil.invoke_ruby(args, test_stdin, false, true, **opt)
-    stderr.force_encoding("ASCII-8BIT")
-
-    if signo = status.termsig
-      sleep 0.1
-      EnvUtil.diagnostic_reports(Signal.signame(signo), EnvUtil.rubybin, status.pid, Time.now)
-    end
-
-    assert_pattern_list(SEGVTest::ExpectedStderrList, stderr, message)
-
-    status
+    assert_in_out_err(args, test_stdin, //, list, encoding: "ASCII-8BIT", **opt)
   end
 
   def test_segv_test